Reversible optical circulator utilizing a bi-morphic piezoelectric apparatus

• US 6,650,801 B1
• Filed: 08/15/2002
• Issued: 11/18/2003
• Est. Priority Date: 02/24/2000
• Status: Expired due to Fees

• Current Assignee: II-VI Incorporated
• Original Assignee: Avanex Corporation (Oclaro (North America), Inc.)
• Inventors: Cao, Simon X. F., Cooney, Thomas, Chen, Weicheng, Wu, Shudong
• Primary Examiner(s): Dunn, Drew A.
• Assistant Examiner(s): BOUTSIKARIS, LEONIDAS
• Application Number:
  US10/222,716
• Time in Patent Office: 460 Days
• Field of Search: 385/11, 385/16, 385/18, 385/19, 359/494, 359/495, 359/501
• US Class Current: 385/16
• CPC Class Codes: G02B 6/2746 comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators magneto-optic non-reciprocal devices G02F1/093
• CPC Class Codes: G02B 6/29302 based on birefringence or polarisation, e.g. wavelength dependent birefringence, polarisation interferometers
• CPC Class Codes: G02B 6/29386 Interleaving or deinterleaving, i.e. separating or mixing subsets of optical signals, e.g. combining even and odd channels into a single optical signal
• CPC Class Codes: G02B 6/3528 the optical element being a prism
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/355 1x2 switch, i.e. one input and a selectable single output of two possible outputs
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: G02B 6/3578 Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system

Abstract

A reversible optical circulator has an optical switch that includes: an arm composed of piezoelectric material with first and second faces and first and second ends, an electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm, a support coupled to the first end of the arm for fixedly supporting the first end, an object with a convex surface coupled to the second end of the arm, a polarization rotation element coupled to the second face of the arm, a first magnet proximately located to the object and the first face of the arm, and a second magnet proximately located to the object and the second face of the arm. By using this optical switch, the optical circulator has stable and reproducible operation, high switching speeds, and low sensitivity to slight optical mis-alignments.

Claims

1. A reversible optical circulator, comprising:

a first port;

a second port; and

a third port, wherein in a first state, light input from the first port is output to the second port and light input from the second port is output to the third port,

wherein in a second state, light input from the third port is output to the second port and light input from the second port is output to the first port,

wherein the first state is switchable to the second state utilizing an optical switch comprising;

an arm comprising a piezoelectric material, the arm comprising a first and a second face and a first and a second end, wherein the first face is opposite to the second face, wherein the first end is opposite to the second end,

at least one electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm,

a support coupled to the first end of the arm for fixedly supporting the first end,

an object with a convex surface coupled to the second end of the arm,

a polarization rotation element coupled to the second face of the arm,

a first magnet proximately located to the object and to the first face of the arm, and

a second magnet proximately located to the object and to the second face of the arm.

2. The circulator of claim 1, wherein the arm comprises:

a first piezoelectric plate; and

a second piezoelectric plate coupled to the first piezoelectric plate in parallel.

3. The circulator of claim 2, wherein the at least one electrode comprises:

a first electrode located between the first and the second piezoelectric plates;

a second electrode coupled to the first piezoelectric plate at a side opposite to the first electrode; and

a third electrode coupled to the second piezoelectric plate at a side opposite to the first electrode.

4. The circulator of claim 1, wherein the support comprises:

a first support member coupled to the first end and the first face of the arm; and

a second support member coupled to the first end and the second face of the arm.

5. The circulator of claim 1, wherein the object comprises:

a first hemisphere coupled to the second end and the first face of the arm; and

a second hemisphere coupled to the second end and the second face of the arm.

6. An optical circulator, comprising:

a first birefringent plate for receiving at least one signal light ray from a first port, wherein the first birefringent plate separates the at least one signal light ray into a plurality of sub-signal rays;

a second birefringent plate optically coupled to the first birefringent plate;

at least one optical rotator optically coupled between the first and second birefringent plates, wherein the at least one optical rotator intercepts a portion of the plurality of sub-signal rays;

at least one reciprocal optical rotator and at least one non-reciprocal optical rotator optically coupled to the second birefringent plate at a side opposite to the at least one optical rotator;

an optical switch optically coupled to the at least one non-reciprocal optical rotator or the at least one reciprocal optical rotator at a side opposite to the second birefringent plate;

a lens optically coupled to the at least one reciprocal optical rotator or the at least one non-reciprocal optical rotator, and the optical switch at a side opposite to the second birefringent plate; and

a mirror optically coupled to the lens at a side opposite to the optical switch,

wherein the mirror reflects the plurality of sub-signal rays such that the plurality of sub-signal rays is folded back upon itself,

wherein the at least one reciprocal optical rotator, the optical switch, the at least one non-reciprocal optical rotator, the at least one optical rotator, and the first and second birefringent plates recombine the reflected plurality of sub-signal rays into the at least one signal light ray, such that the recombined at least one signal light ray is directed to a second port.

7. The circulator of claim 6, wherein the optical switch comprises:

an arm comprising a piezoelectric material, the arm comprising a first and a second face and a first and a second end, wherein the first face is opposite to the second face, wherein the first end is opposite to the second end;

at least one electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm;

a support coupled to the first end of the arm for fixedly supporting the first end;

an object with a convex surface coupled to the second end of the arm;

an optical element coupled to the second face of the arm capable of deflecting an optical signal traveling therethrough;

a first magnet proximately located to the object and to the first face of the arm; and

a second magnet proximately located to the object and to the second face of the arm.

8. The circulator of claim 7, wherein the arm comprises:

a first piezoelectric plate; and

a second piezoelectric plate coupled to the first piezoelectric plate in parallel.

9. The circulator of claim 8, wherein the at least one electrode comprises:

a first electrode located between the first and the second piezoelectric plates;

a second electrode coupled to the first piezoelectric plate at a side opposite to the first electrode; and

a third electrode coupled to the second piezoelectric plate at a side opposite to the first electrode.

10. The circulator of claim 7, wherein the support comprises:

a first support member coupled to the first end and the first face of the arm; and

a second support member coupled to the first end and the second face of the arm.

11. The circulator of claim 7, wherein the object comprises:

a first hemisphere coupled to the second end and the first face of the arm; and

a second hemisphere coupled to the second end and the second face of the arm.

12. The circulator of claim 7, wherein the optical element comprises a switchable 90 degree optical rotation element.

13. A system for directing a signal light ray, comprising:

an optical network, the optical network comprising the signal light ray; and

an optical circulator, comprising;

a first birefringent plate for receiving at least one signal light ray from a first port, wherein the first birefringent plate separates the at least one signal light ray into a plurality of sub-signal rays;

a second birefringent plate optically coupled to the first birefringent plate;

at least one optical rotator optically coupled between the first and second birefringent plates, wherein the at least one optical rotator intercepts a portion of the plurality of sub-signal rays;

at least one reciprocal optical rotator and at least one non-reciprocal optical rotator optically coupled to the second birefringent plate at a side opposite to the at least one optical rotator;

an optical switch optically coupled to either the at least one non-reciprocal optical rotator or the at least one non-reciprocal optical rotator at a side opposite to the second birefringent plate;

a lens optically coupled to the at least one reciprocal optical rotator or the non-reciprocal optical rotator, and the optical switch at a side opposite to the second birefringent plate; and

a mirror optically coupled to the lens at a side opposite to the optical switch,

wherein the mirror reflects the plurality of sub-signal rays such that the plurality of sub-signal rays is folded back upon itself,

wherein the at least one reciprocal optical rotator, the optical switch, the at least one non-reciprocal optical rotator, the at least one optical rotator, and the first and second birefringent plates recombine the reflected plurality of sub-signal rays into the at least one signal light ray, such that the recombined at least one signal light ray is directed to a second port.

14. The system of claim 13, wherein the optical switch comprises:

an arm comprising a piezoelectric material, the arm comprising a first and a second face and a first and a second end, wherein the first face is opposite to the second face, wherein the first end is opposite to the second end;

at least one electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm;

a support coupled to the first end of the arm for fixedly supporting the first end;

an object with a convex surface coupled to the second end of the arm;

an optical element coupled to the second face of the arm capable of deflecting an optical signal traveling therethrough;

a first magnet proximately located to the object and to the first face of the arm; and

a second magnet proximately located to the object and to the second face of the arm.

15. A method for directing a signal light ray, comprising the steps of:

(a) separating the signal light ray into a plurality of sub-signal rays, wherein the signal light ray is inputted from a first port;

(b) rotating a polarization direction of a portion of the plurality of sub-signal rays utilizing an optical switch comprising a switchable 90 degree rotation element, wherein the utilizing an optical switch comprising a switchable 90 degree rotation element, wherein the optical switch comprises;

an arm comprising a piezoelectric material, the arm comprising a first and a second face and a first and a second end, wherein the first face is opposite to the second face, wherein the first end is opposite to the second end,

at least one electrode coupled to the arm for providing a voltage difference between the first and second faces of the arm,

a support coupled to the first end of the arm for fixedly supporting the first end,

an object with a convex surface coupled to the second end of the arm,

an optical element coupled to the second face of the arm capable of deflecting an optical signal traveling therethrough,

a first magnet proximately located to the object and to the first face of the arm, and

a second magnet proximately located to the object and to the second face of the arm;

(c) reflecting the rotated portion and a remainder of the plurality of sub-signal rays, such that the rotated portion and the remainder are folded back upon themselves; and

(d) combining the rotated portion and the remainder of the plurality of sub-signal rays into the signal light ray, wherein the signal light ray is outputted to a second port.